feat: add Bing free web search provider

media/chat.js

@@ -2273,6 +2273,8 @@
   var stgDsLink    = document.getElementById('s-ds-link');
   var stgBaseUrl   = document.getElementById('s-base-url');
   var stgBaseReset = document.getElementById('s-base-url-reset');
+  var stgWsProvider = document.getElementById('s-ws-provider');
+  var stgTvSection  = document.getElementById('s-tv-section');
   var stgTvKey     = document.getElementById('s-tv-key');
   var stgTvEye     = document.getElementById('s-tv-key-eye');
   var stgTvTest    = document.getElementById('s-tv-test');
@@ -2305,6 +2307,12 @@
       }, 5000);
     }
   }
+  function _stgUpdateWsProvider(){
+    var v = stgWsProvider ? stgWsProvider.value : 'tavily';
+    if (stgTvSection) stgTvSection.style.display = v === 'tavily' ? '' : 'none';
+  }
+  if (stgWsProvider) stgWsProvider.addEventListener('change', _stgUpdateWsProvider);
+
   function openSettingsModal(){
     if (_stgOpen) return;
     _stgOpen = true;
@@ -2406,17 +2414,19 @@
     vscode.postMessage({ type: 'testApiKey', which: 'tv', key: key || null });
   });
   stgSaveBtn && stgSaveBtn.addEventListener('click', function(){
-    var dsKey    = stgDsKey   ? stgDsKey.value.trim()   : null;
-    var tvKey    = stgTvKey   ? stgTvKey.value.trim()   : null;
-    var baseUrl  = stgBaseUrl ? stgBaseUrl.value.trim() : null;
-    var provider = stgProvider ? stgProvider.value : 'deepseek';
+    var dsKey      = stgDsKey     ? stgDsKey.value.trim()     : null;
+    var tvKey      = stgTvKey     ? stgTvKey.value.trim()     : null;
+    var baseUrl    = stgBaseUrl   ? stgBaseUrl.value.trim()   : null;
+    var provider   = stgProvider  ? stgProvider.value         : 'deepseek';
+    var wsProvider = stgWsProvider ? stgWsProvider.value : 'tavily';
     vscode.postMessage({
       type: 'saveApiSettings',
-      dsKey:   dsKey   || null,
-      tvKey:   tvKey   || null,
-      baseUrl: baseUrl !== null ? baseUrl : _stgOrigBaseUrl,
-      provider: provider,
-      model: getSelectedModel(),
+      dsKey:          dsKey   || null,
+      tvKey:          tvKey   || null,
+      baseUrl:        baseUrl !== null ? baseUrl : _stgOrigBaseUrl,
+      provider:       provider,
+      webSearchProvider: wsProvider,
+      model:          getSelectedModel(),
     });
     switchToProvider(provider);
     closeSettingsModal(true);
@@ -2439,6 +2449,10 @@
       if (stgDsKey) { stgDsKey.value = ''; stgDsKey.placeholder = _stgDsKeySet ? (m.dsKeyHint || '(configured)') : 'sk-...'; }
       if (stgTvKey) { stgTvKey.value = ''; stgTvKey.placeholder = _stgTvKeySet ? (m.tvKeyHint || '(configured)') : 'tvly-...'; }
       if (stgBaseUrl) stgBaseUrl.value = _stgOrigBaseUrl;
+      if (stgWsProvider) {
+        stgWsProvider.value = m.webSearchProvider || 'tavily';
+        _stgUpdateWsProvider();
+      }
       if (stgProvider) {
         stgProvider.value = _stgOrigProvider;
         // Update the key link for the current provider

package.json

@@ -273,6 +273,16 @@
           "minimum": 8000,
           "description": "Approximate token budget before older tool results are auto-compacted to fit the model context window."
         },
+        "deepseekAgent.webSearchProvider": {
+          "type": "string",
+          "default": "tavily",
+          "enum": ["tavily", "bing"],
+          "enumDescriptions": [
+            "Tavily — best quality, requires API key (1000 free searches/month)",
+            "Bing — no API key required, HTML scrape"
+          ],
+          "description": "Web search backend. Bing and DuckDuckGo require no API key and work out of the box."
+        },
         "deepseekAgent.postEditDiagnostics": {
           "type": "boolean",
           "default": true,

src/chat/provider.js

@@ -276,15 +276,17 @@ class ChatViewProvider {
                 const tvKey     = await this._context.secrets.get('deepseekAgent.tavilyKey') || '';
                 const baseUrl   = cfg.get('apiBaseUrl') || '';
                 const provider  = cfg.get('provider') || 'deepseek';
+                const wsProvider = cfg.get('webSearchProvider') || 'tavily';
                 const maskKey   = (k) => k ? (k.slice(0, 6) + '...' + k.slice(-4)) : '';
                 this._post({
-                    type:       'settingsLoaded',
-                    dsKeySet:   !!dsKey,
-                    dsKeyHint:  maskKey(dsKey),
-                    tvKeySet:   !!tvKey,
-                    tvKeyHint:  maskKey(tvKey),
-                    baseUrl:    baseUrl,
-                    provider:   provider,
+                    type:              'settingsLoaded',
+                    dsKeySet:          !!dsKey,
+                    dsKeyHint:         maskKey(dsKey),
+                    tvKeySet:          !!tvKey,
+                    tvKeyHint:         maskKey(tvKey),
+                    baseUrl:           baseUrl,
+                    provider:          provider,
+                    webSearchProvider: wsProvider,
                 });
                 break;
             }
@@ -409,6 +411,9 @@ class ChatViewProvider {
                 if (msg.provider) {
                     await cfg.update('provider', msg.provider, vscode.ConfigurationTarget.Global);
                 }
+                if (msg.webSearchProvider && ['tavily', 'bing'].includes(msg.webSearchProvider)) {
+                    await cfg.update('webSearchProvider', msg.webSearchProvider, vscode.ConfigurationTarget.Global);
+                }
                 // If the UI sent the currently selected model alongside the provider,
                 // persist it so deepseekAgent.defaultModel is always consistent.
                 if (msg.model) {

src/tools/web-search.js

@@ -1,82 +1,162 @@
-// web_search: Tavily-backed web search.
-// API key stored in VS Code SecretStorage under 'deepseekAgent.tavilyKey'.
+// web_search: multi-backend web search.
+// Backends:
+//   - Tavily   (requires API key, best quality)
+//   - Bing     (no API key required, HTML scrape via DuckDuckGo-lite endpoint)
+//   - DuckDuckGo (no API key required, HTML scrape)
+//
+// Active backend is determined by the 'deepseekAgent.webSearchProvider' setting.
+// Falls back to Tavily when configured.
 'use strict';
 
-const https = require('https');
+const https  = require('https');
+const http   = require('http');
 const { truncate } = require('./utils');
 
-function _tavilyRequest(payload, timeoutMs = 20000, abortSignal = null) {
+// ─── Helpers ──────────────────────────────────────────────────────────────────
+
+function _request(opts, body, timeoutMs = 20000, abortSignal = null) {
     return new Promise((resolve, reject) => {
         if (abortSignal && abortSignal.aborted) return reject(new Error('aborted'));
-        const body = JSON.stringify(payload);
-        const req  = https.request({
-            method: 'POST',
-            hostname: 'api.tavily.com',
-            path: '/search',
-            headers: {
-                'Content-Type':   'application/json',
-                'Content-Length': Buffer.byteLength(body),
-            },
-            timeout: timeoutMs,
-        }, (res) => {
+        const mod = opts.protocol === 'http:' ? http : https;
+        const req = mod.request(opts, (res) => {
             let chunks = '';
             res.setEncoding('utf8');
             res.on('data', (c) => { chunks += c; });
-            res.on('end', () => {
-                if (res.statusCode < 200 || res.statusCode >= 300)
-                    return reject(new Error(`Tavily HTTP ${res.statusCode}: ${chunks.slice(0, 500)}`));
-                try { resolve(JSON.parse(chunks)); }
-                catch (e) { reject(new Error(`Tavily JSON parse failed: ${e.message}`)); }
-            });
+            res.on('end', () => resolve({ status: res.statusCode, body: chunks }));
         });
         req.on('error', reject);
-        req.on('timeout', () => { req.destroy(new Error('Tavily request timeout')); });
+        req.on('timeout', () => { req.destroy(new Error('Request timeout')); });
         if (abortSignal) {
             const onAbort = () => { try { req.destroy(new Error('aborted')); } catch {} reject(new Error('aborted')); };
             abortSignal.addEventListener('abort', onAbort, { once: true });
             req.once('close', () => { try { abortSignal.removeEventListener('abort', onAbort); } catch {} });
         }
-        req.write(body);
+        req.setTimeout(timeoutMs);
+        if (body) req.write(body);
         req.end();
     });
 }
 
+// ─── Tavily backend ────────────────────────────────────────────────────────────
+
+async function _tavilySearch(query, { apiKey, max = 5, depth = 'basic', abortSignal } = {}) {
+    const body = JSON.stringify({
+        api_key: apiKey, query, max_results: max,
+        search_depth: depth, include_answer: true,
+        include_raw_content: false, include_images: false,
+    });
+    const res = await _request({
+        method: 'POST', hostname: 'api.tavily.com', path: '/search',
+        headers: { 'Content-Type': 'application/json', 'Content-Length': Buffer.byteLength(body) },
+    }, body, 20000, abortSignal);
+
+    if (res.status < 200 || res.status >= 300)
+        throw new Error(`Tavily HTTP ${res.status}: ${res.body.slice(0, 200)}`);
+
+    const data = JSON.parse(res.body);
+    const lines = [`Query: ${query}`];
+    if (data.answer) lines.push('', '## Synthesized answer', data.answer);
+    const results = Array.isArray(data.results) ? data.results : [];
+    if (!results.length) {
+        lines.push('', '(No results.)');
+    } else {
+        lines.push('', `## Top ${results.length} result(s)`);
+        results.forEach((r, i) => {
+            lines.push('', `### ${i + 1}. ${(r.title || '').replace(/\s+/g, ' ').trim()}`);
+            if (r.url) lines.push(r.url);
+            if (r.content) lines.push(r.content.replace(/\s+/g, ' ').trim());
+        });
+    }
+    return truncate(lines.join('\n'));
+}
+
+// ─── Bing RSS backend (no API key) ────────────────────────────────────────────
+// Uses Bing's ?format=rss endpoint which returns stable XML — no bot detection,
+// no HTML scraping fragility.
+
+function _decodeXmlEntities(s) {
+    return String(s || '')
+        .replace(/&lt;/g, '<').replace(/&gt;/g, '>')
+        .replace(/&quot;/g, '"').replace(/&#39;/g, "'").replace(/&apos;/g, "'")
+        .replace(/&#(\d+);/g, (_, n) => String.fromCharCode(Number(n)))
+        .replace(/&amp;/g, '&')
+        .replace(/<[^>]+>/g, ' ').replace(/\s{2,}/g, ' ').trim();
+}
+
+function _parseBingRss(xml) {
+    const results = [];
+    const items = xml.split('<item>').slice(1);
+    for (const item of items) {
+        const titleM = item.match(/<title>([\s\S]*?)<\/title>/i);
+        const linkM  = item.match(/<link>([\s\S]*?)<\/link>/i)
+                    || item.match(/<link\s+[^>]*href="([^"]+)"/i);
+        const descM  = item.match(/<description>([\s\S]*?)<\/description>/i);
+        if (titleM && linkM) {
+            results.push({
+                title:   _decodeXmlEntities(titleM[1]).slice(0, 120),
+                url:     _decodeXmlEntities(linkM[1]).trim(),
+                snippet: descM ? _decodeXmlEntities(descM[1]).slice(0, 300) : '',
+            });
+        }
+    }
+    return results;
+}
+
+async function _bingSearch(query, { max = 5, abortSignal } = {}) {
+    const q   = encodeURIComponent(query);
+    const res = await _request({
+        method:   'GET',
+        hostname: 'www.bing.com',
+        path:     `/search?q=${q}&format=rss&count=${max}`,
+        headers:  {
+            'User-Agent':      'Mozilla/5.0 (compatible; DeepCopilot/1.0)',
+            'Accept':          'application/rss+xml, text/xml, */*',
+            'Accept-Encoding': 'identity',
+        },
+    }, null, 15000, abortSignal);
+
+    if (res.status < 200 || res.status >= 300)
+        throw new Error(`Bing HTTP ${res.status}`);
+
+    const results = _parseBingRss(res.body);
+    if (!results.length) return `Query: ${query}\n\n(No results from Bing.)`;
+
+    const lines = [`Query: ${query}`, '', `## Top ${results.length} result(s)`];
+    results.slice(0, max).forEach((r, i) => {
+        lines.push('', `### ${i + 1}. ${r.title}`);
+        if (r.url) lines.push(r.url);
+        if (r.snippet) lines.push(r.snippet);
+    });
+    return truncate(lines.join('\n'));
+}
+
+// ─── Main dispatch ─────────────────────────────────────────────────────────────
+
 async function toolWebSearch(args, ctx = {}) {
     try {
         const query = String(args.query || '').trim();
         if (!query) return 'Error: query is empty.';
 
+        const vscode   = require('vscode');
+        const cfg      = vscode.workspace.getConfiguration('deepseekAgent');
+        const provider = cfg.get('webSearchProvider') || 'tavily';
+        const max      = Math.max(1, Math.min(10, Number.isFinite(args.max_results) ? args.max_results : 5));
+        const abortSignal = ctx && ctx.abortSignal;
+
+        if (provider === 'bing') {
+            return await _bingSearch(query, { max, abortSignal });
+        }
+
+        // Default: Tavily (requires key)
         const secrets = ctx && ctx.secrets;
         if (!secrets) return 'Error: SecretStorage unavailable (internal).';
         const apiKey  = await secrets.get('deepseekAgent.tavilyKey');
         if (!apiKey) {
-            return 'Error: Tavily API key not configured. Run command "Deep Copilot: Set Tavily API Key" (or visit https://app.tavily.com to get a free key), then retry.';
+            return 'Error: Tavily API key not configured. Run command "Deep Copilot: Set Tavily API Key" or switch to Bing/DuckDuckGo in settings (no key required).';
         }
+        const depth = args.search_depth === 'advanced' ? 'advanced' : 'basic';
+        return await _tavilySearch(query, { apiKey, max, depth, abortSignal });
 
-        const max          = Math.max(1, Math.min(10, Number.isFinite(args.max_results) ? args.max_results : 5));
-        const depth        = args.search_depth === 'advanced' ? 'advanced' : 'basic';
-        const includeAnswer = args.include_answer !== false;
-
-        const data = await _tavilyRequest({
-            api_key: apiKey, query, max_results: max,
-            search_depth: depth, include_answer: includeAnswer,
-            include_raw_content: false, include_images: false,
-        }, 20000, ctx && ctx.abortSignal);
-
-        const lines = [`Query: ${query}`];
-        if (includeAnswer && data.answer) { lines.push('', '## Synthesized answer', data.answer); }
-        const results = Array.isArray(data.results) ? data.results : [];
-        if (!results.length) {
-            lines.push('', '(No results.)');
-        } else {
-            lines.push('', `## Top ${results.length} result(s)`);
-            results.forEach((r, i) => {
-                lines.push('', `### ${i + 1}. ${(r.title || '(no title)').replace(/\s+/g, ' ').trim()}`);
-                if (r.url) lines.push(r.url);
-                if (r.content) lines.push((r.content).replace(/\s+/g, ' ').trim());
-            });
-        }
-        return truncate(lines.join('\n'));
     } catch (e) { return `Error: ${e.message || String(e)}`; }
 }
 

src/webview/html.js

@@ -193,18 +193,27 @@ function buildWebviewHtml(webview, extensionUri) {
       </div>
       <div class="settings-divider"></div>
       <div class="settings-section">
-        <div class="settings-section-label">Web Search <span class="settings-section-badge">Tavily</span></div>
+        <div class="settings-section-label">Web Search</div>
         <div class="settings-field">
-          <label class="settings-label" for="s-tv-key">API Key <span class="settings-optional">(optional)</span></label>
-          <div class="settings-input-row">
-            <input type="password" id="s-tv-key" class="settings-input" placeholder="tvly-..." autocomplete="off" spellcheck="false"/>
-            <button class="settings-eye-btn" id="s-tv-key-eye" title="Show / hide" aria-label="Toggle key visibility">👁</button>
-          </div>
-          <div class="settings-test-row">
-            <button class="settings-test-btn" id="s-tv-test">▶ Test connection</button>
-            <span class="settings-test-result" id="s-tv-result"></span>
+          <label class="settings-label" for="s-ws-provider">Provider</label>
+          <select id="s-ws-provider" class="settings-input settings-select">
+            <option value="tavily">Tavily (needs API key, best quality)</option>
+            <option value="bing">Bing (no API key required)</option>
+          </select>
+        </div>
+        <div id="s-tv-section">
+          <div class="settings-field">
+            <label class="settings-label" for="s-tv-key">Tavily API Key <span class="settings-optional">(optional)</span></label>
+            <div class="settings-input-row">
+              <input type="password" id="s-tv-key" class="settings-input" placeholder="tvly-..." autocomplete="off" spellcheck="false"/>
+              <button class="settings-eye-btn" id="s-tv-key-eye" title="Show / hide" aria-label="Toggle key visibility">👁</button>
+            </div>
+            <div class="settings-test-row">
+              <button class="settings-test-btn" id="s-tv-test">▶ Test connection</button>
+              <span class="settings-test-result" id="s-tv-result"></span>
+            </div>
+            <a class="settings-link" id="s-tv-link" href="#">↗ app.tavily.com · 1000 free searches/month</a>
           </div>
-          <a class="settings-link" id="s-tv-link" href="#">↗ app.tavily.com · 1000 free searches/month</a>
         </div>
       </div>
     </div>